Development and Flight Testing of a Wireless Avionics Network Based on the IEEE 802.11 Protocols

Abstract

This report describes the development and flight testing of the IEEE 802.11 protocol-based Wireless Flight Management System (WFMS) using low cost Commercial-Off-The-Shelf (COTS) equipment and software. The unlicensed spectrum allocation in the 2.4 GHz and 5 GHz bands by the FCC has encouraged the industry to develop new standards for short-range communication that are commercially viable. This has resulted in new short-range communication technologies like Bluetooth and the Wireless Local Area Network (WLAN). The new modulation techniques developed for wireless communication support wired equivalent data rates. The commercial success of these technologies and their wide market adaptation has resulted in reduced costs for the devices that support these technologies. Applications of wireless technology in aerospace engineering are vast, including development, testing, manufacturing, prognostics health management, ground support equipment and active control. The high data rates offered by technologies like WLAN (IEEE 802.11 a/b/g) are sufficient to implement critical and essential data applications of avionics systems. A wireless avionics network based on IEEE 802.11a/b/g protocols will reduce the complexity and cost of installation and maintenance of the avionics system when compared to the existing wired system. The proposed WFMS imitates the flight management system of any commercial aircraft in terms of functionality. It utilizes a radio frequency for the transmission of the sensor data to the Cockpit Display Unit (CDU) and the Flight Management Computer (FMC). WFMS consists of a FMC, data acquisition node, sensor node and a user interface node. The FMC and the data acquisition nodes are built using PC/104 standard modules. The sensor node consists of an Attitude and Heading Reference System (AHRS) and a GPS integrated with a serial device server. The user interface node is installed with moving map software which receives data from the AHRS and GPS to display flight information including topographic maps, attitude, heading, velocity, et cetera. This thesis demonstrates the performance evaluation of the WFMS both on the ground and in flight, and its advantages over a wired system. This thesis focuses on the evaluation of IEEE 802.11a/b/g protocols for avionics application. Efforts taken to calibrate the available bandwidth of the WLAN network at different operating conditions and varying ranges using different network analysis tools are explained briefly. Considerable research on issues like electromagnetic interference and network security critical to the development of a wireless network for avionics has also been done. This report covers different aspects of the implementation of wireless technology for aircraft systems. This work is a successful starting point for the new fly-by-wireless concept with extensions to active wireless flight control.